1. Field of the Invention
The present invention relates to a band refeeding method in a banding packing machine and the banding packing machine having a refeeding mechanism. More particularly, this invention relates to a band refeeding method in a banding packing machine and the banding packing machine having a refeeding mechanism in which a band is fed to a predetermined position on the band guide arch side and in this state, when the band does not reach the predetermined position, the band is once returned and is then fed again and supplied to the predetermined position.
2. Description of the Related Art
As shown in FIGS. 5 and 6, for example, in a full automatic type banding packing machine 20, a band guide arch 22 for guiding a band like a loop around an article 36 to be packed is provided above a packing machine body 21. Moreover, a band reel 25 having a large amount of band B wound therearound is provided on the side surface of the packing machine body 21.
On the other hand, a pool box 24 is formed by partition under the front surface of the packing machine body 21.
Moreover, as shown in FIG. 6, a control portion 28 provided on the upper part of the packing machine body 21 includes band supply means 30 having a pair of rollers for supplying the band B toward the band guide arch 22 side, band pull back means 31 having a pair of rollers for pulling back the band from the band guide arch 22 side conversely, and band tightening means 32 for further tightening the band thus pulled back. The band supply means 30 is constituted by a normal rotating roller 30a for normal rotating and a touch roller 30b to come in pressure contact therewith. Furthermore, the band pull back means 31 and the band tightening means 32 are constituted by a reverse rotating roller 32a and a touch roller 30b to come in pressure contact therewith.
The touch roller 30b is operated by a link 40, thereby coming in pressure contact with the normal rotating roller 30a or the reverse rotating roller 32a. In FIG. 6, for convenience, the touch roller 30b is shown in an abutting state on the reverse rotating roller 32a. 
Furthermore, in the control portion 28, the tip portion of the band B, which surrounds the article 36 to be packed, is interposed between the tip portion of a right presser member 42 capable of vertically moving and a slide table 37 below the band guide arch 22. Then, a band guide 34 supported to freely appear by a shaft is moved backward from below the slide table 37 in the interposition state between the right presser member 42 and the slide table 37. Thereafter, the band B is pulled back toward the pool box 24 side by the band pull back means 31 and is further tightened by the band tightening means 32. Furthermore, a left presser member 39 is moved upward to maintain the band B to be tightened between the left presser member 39 and the slide table 37. Then, a middle presser member 41 is moved upward to lift the band B, thereby cutting the rear end side of the band B by means of a cutter 41a. A heater is inserted to freely appear in a horizontal direction in the superposing portion of the band, thereby melting the surface of the superposing portion of the band. Furthermore, the middle presser member 41 is successively lifted to bond the superposing portion of the band between the middle presser member 41 and the slide table 37.
The reference numeral 43 in FIG. 6 denotes a stopper provided in the band guide 34. When the tip portion of the band reaches the stopper 43 and a limit switch is turned ON, the band is subsequently pulled back by the band pull back means 31 based on a signal. Furthermore, the band is tightened by the band tightening means 32 and the cutting and welding operations of the band are further carried out in order in a predetermined timing while they are controlled by a cam mechanism (not shown) for controlling the vertical movement of the right presser member 42, the left presser member 39, the middle presser member 41 and the like. The cam mechanism for controlling the vertical movement of the right presser member 42, the left presser member 39 and the middle presser member 41 is constituted between respective cam followers attached to the lower parts of the right presser member 42, the left presser member 39 and the middle presser member 41 and a cam shaft (not shown) provided with cams corresponding to the cam followers (see FIG. 4).
In the conventional banding machine 20, the band B is supplied toward the band guide arch 22 side by the band supply means 30. If the tip portion of the band B is twisted, it cannot reach the stopper 43 but is stopped in the middle of the band guide arch 22, for example.
In such a case, that is, in the case in which the tip of the band B does not reach the stopper 43 of the band guide 34 even if a predetermined time passes, the band pull back means 31 is automatically operated to once pull back the tip portion of the band B from the band guide arch 22 and to supply the band by the band supply means 30 again. As a result, the band is fed toward the band guide arch 22 side again.
However, in the conventional banding packing machine 20, in some cases in which the band B is further pulled back by the band pull back means 31 side, the tip portion of the band B vigorously passes not only through the band pull back means 31, but also through the normal rotating roller 30a of the band supply means 30. If the tip portion of the band B pulled back thus gets over the peripheral surface of the normal rotating roller 30a, the band cannot be supplied by the band supply means 30 again. As a result, an operator must search for the tip portion of the band from the inner part of the packing machine body, and guide the tip portion of the band to a correct position passing through a portion between the normal rotating roller 30a and the touch roller 30b. 